Fertilizing Blackberry Plants – Learn When To Fertilize Blackberry Bushes

Close Up Of Blackberries
blackberry fertilizer
(Image credit: flowersandclassicalmusic)

If you want to grow your own fruit, a great place to start is by growing blackberries. Fertilizing your blackberry plants will give you the highest yield and the largest juiciest fruit, but how do you fertilize your blackberry bushes? Read on to find out when to fertilize blackberry bushes and other specific blackberry feeding requirements.

How to Fertilize Blackberries

Berries, in general, are nutritious, and blackberries have been shown to help fight cancer and cardiovascular disease as well as slow down the aging of the brain. Today’s new cultivars can even be found thornless, erasing those memories of torn clothing and scratched skin while harvesting their wild brethren. 

Easier to harvest, they may be, but to get that bumper crop, you need fertilizer for blackberries. First things first, though. Plant your berries in full sun, allowing plenty of room to grow. The soil should be well-draining, sandy loam rich in organic matter. Decide if you want trailing, semi-trailing, or erect berries and thorny or thornless. 

All blackberries benefit from a trellis or support so have that in place as well. How many plants should you get? Well, a single, healthy blackberry plant can supply up to 10 pounds (4.5 kg.) of berries per year!

When to Fertilize Blackberries

Now that you have planted your selections, what are the feeding requirements for your new blackberries? You don’t begin fertilizing blackberry plants until three to four weeks after the setting of new plants. 

Fertilize after growth starts. Use a complete fertilizer, like 10-10-10, in the amount of 5 pounds (2.5 kg.) per 100 linear feet (30.5 m.) or 3 to 4 ounces (85-113 g.) around the base of each blackberry. Use either a complete 10-10-10 food as fertilizer for your blackberries or use compost, manure, or another organic fertilizer

Apply 50 pounds (23 kg.) of organic fertilizer per 100 feet (30.5 m.) in the late fall prior to the first frost. As growth starts to appear in early spring, spread inorganic fertilizer over the top of the soil in each row in the same amount as above of 5 pounds (2.5 kg.) of 10-10-10 per 100 feet (30.5 m.). 

Some folks say to fertilize three times a year and some say once in the spring and once in the late fall before the first frost. The blackberries will let you know if you need supplemental feeding. Look at their leaves and determine if the plant is fruiting and growing well. If so, no fertilizing of the blackberry plants is necessary.

Amy Grant

Amy Grant has been gardening for 30 years and writing for 15. A professional chef and caterer, Amy's area of expertise is culinary gardening.